This invention relates to certain improvements in tire presses of the type shown in prior U.S. Pat. Nos. 4,338,069 and 4,447,385. Such tire presses are representative of tire presses manufactured as sold by NRM Corporation of Columbiana, Ohio, under the well known trademark AUTOLOK.
More importantly, in U.S. Pat. No. 4,338,069 there is illustrated in some detail a loader for such press which utilizes parallel rods for vertically moving the loader basket and which includes a mechanism for synchronizing the movement of the loader with the bottom bead ring. Such mechanism involves a fairly complex cable assembly which was found to be adequate for its intended purpose. However, the cable assembly of such prior art presses was found to corrode in the field due to the steam-water environment of tire curing presses. The cable was also quite complex to adjust and was costly to manufacture and install.
Moreover, the loaders of such prior art patents were found difficult to manufacture with the required tolerances for precision loading since it was difficult to manufacture two parallel plumb rods for vertical movement of the horizontally extending loader frame. Such prior art constructions not only were expensive and difficult to manufacture and adjust, but also resulted in less than the desired concentricity and alignment in tire press loading. While satisfactory for some purposes, such prior art mechanisms were not completely satisfactory for both manufacturing economies and the desired results.
In any event it is desirable to have a loader or a tire press which will position the green tire in the proper relationship with an elevated bottom bead ring and which will move that green tire in synchronism with the vertical movement of that bottom bead ring. This is true whether the vertical movement of the green tire is accomplished by the loader itself moving in synchronism with the bottom bead ring or by a top loading mechanism in which the loader has transferred the green tire to the top bead ring which then moves in synchronism as the press closes with the bottom bead ring. It is also desirable to drive the loader with a power driven mechanism which may be stalled to be in synchronism with the vertical movement of the bottom bead ring.
Prior attempts to drive a loader by such mechanism such as shown in U.S. Pat. No. 4,391,769 or even to drive a bladder by such mechanism as shown in U.S. Pat. No. 4,368,015 have fallen far short of the requirements of the present invention. There have even been attempts to synchronize the shaping of the tire with the closing of the press head such as shown in U.S. Pat. No. 3,609,812 to Baier.